<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>

    </style>

    <script src="./react/react.development.js"></script>
    <script src="./react/react-dom.development.js"></script>
    <script src="./react/babel.min.js"></script>
    <script src="./react/prop-types.js"></script>
</head>
<body>
<div id="app"></div>
<script type="text/babel">

    //JSX=JS+xml、
    let app = document.querySelector('#app');
    let root = ReactDOM.createRoot(app);

    class Welcome extends React.Component{
        handleClick = (ev) =>{
            console.log(ev)
            console.log(this)
        }

        handleClick2 = (num) =>{
            return (ev)=>{
                console.log(num)
            }
        }
        render(){

            return(
                <div>
                   <!--<button onClick={this.handleClick}>点击</button>-->
                    <button onClick={this.handleClick2(1)}>点击</button>

                </div>
            )
        }
    }

    let info = {
        msg: 'hi react',
        username: 'lwj',
        age : '20'
    }

    let element = (<Welcome msg = "hi react class"/>)
    element = (<Welcome />)

    root.render(element);

</script>
</body>
</html>